This work is designed to investigate how genes determine lifespan in a reasonably complicated metayaan organism. My approach is to try to isolate mutant organisms that live longer than normal, then to characterize the mutants genetically, physiologically and biochemically to try to find out why they live longer. I am also characterizing development and aging in wild-type (normal) organisms under various conditions as background data to help in isolating and understanding mutants. We have shown that the nematode C. elegans undergoes predictable changes as it ages, including shut-down of gonad function, slower rate of feeding and slower movement. We have also developed procedures for growing large quantities of age-synchronized worms. We are now trying to develop ways to select for mutant organisms in age-synchronized populations that shown delayed onset of the age-related changes mentioned. Such organisms will be examined to see if they live longer.